The Materialis Companion plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's materialis_contact_form shortcode in all versions up to, and including, 1.3.41 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The Materialis Companion WordPress plugin before 1.3.40 does not validate and escape some of its shortcode attributes before outputting them back in the page, which could allow users with a role as low as contributor to perform Stored Cross-Site Scripting attacks which could be used against high privilege users such as admins.